Explain the differences between the 'State' and 'Strategy' design patterns in object-oriented programming.

The design patterns "State" and "Strategy" are similar in that both use polymorphism to change an object's behavior, but they differ in purpose and context of use.

• Strategy: Allows selecting an algorithm or behavior at runtime, encapsulating different options into separate classes. The context object delegates execution to the chosen strategy.

  Example: a sorting class that can use different algorithms (quick sort, merge sort, etc.), chosen dynamically.

• State: Allows an object to change its behavior when its internal state changes, making it appear as if it has changed its class. Each state class implements behavior corresponding to that state.

  Example: a media player that behaves differently in "Playing," "Paused," and "Stopped" states.

Key difference:

• Strategy changes the algorithm without changing the object's state.
• State changes the object's behavior depending on its internal state.

In Java, this is usually implemented through interfaces and classes implementing these interfaces, which are passed or changed within the context.